| Title: |
An assay for aryl radicals using BHAS coupling |
| Authors: |
Clark, Kenneth F.; Tyerman, Seb; Evans, Laura; Robertson, Craig M.; Murphy, John A. |
| Publication Year: |
2024 |
| Collection: |
University of Strathclyde Glasgow: Strathprints |
| Subject Terms: |
Organic chemistry |
| Description: |
Aryl radicals are intermediates in many reactions, but determining their presence unambiguously is often challenging. As we recently reported, reaction of 2-iodo-1,3-dimethylbenzene (7) in benzene with KOtBu and a suitable organic additive, leads to a base-induced homolytic aromatic substitution (BHAS) coupling reaction giving 2,6-dimethylbiphenyl (12) and biphenyl (3) as coupled products, together with xylene (13). In this case, biphenyl arises from a radical translocation and is the major coupling product. This paper now quantitatively investigates that reaction, which shows a very similar ratio for 3 : 12 [ca. 4 : 1] when using different sources of radical initiation. Deuterium isotope studies provide detailed mechanistic support for the proposed mechanism; when carried out in C6D6 vs. C6H6, the reaction is characterised by a strong isotope effect for formation of 3-d10 vs. 3, but not for formation of 12-d5 vs. 12. These distinctive properties mean that the transformation can act as an assay for aryl radicals. An advantage of such a BHAS process is its sensitivity, since it involves a chain reaction that can amplify radical activity. |
| Document Type: |
article in journal/newspaper |
| File Description: |
text |
| Language: |
unknown |
| ISSN: |
1477-0520 |
| Relation: |
https://strathprints.strath.ac.uk/87792/7/Clark-etal-OBC-2023-An-assay-for-aryl-radicals-using-BHAS-coupling.pdf; Clark, Kenneth F. and Tyerman, Seb and Evans, Laura and Robertson, Craig M. and Murphy, John A. (2024 ) An assay for aryl radicals using BHAS coupling. Organic and Biomolecular Chemistry , 22 (5). pp. 1018-1022. ISSN 1477-0520 |
| DOI: |
10.1039/D3OB01743E |
| Availability: |
https://strathprints.strath.ac.uk/87792/; https://doi.org/10.1039/D3OB01743E |
| Rights: |
cc_by_3 |
| Accession Number: |
edsbas.3877AE10 |
| Database: |
BASE |